1. Field of the Invention
The present invention relates to a device for the inspection and quality control of wire rope and cables. The device is adapted to concentrically surround a portion of a wire rope or cable to be tested. The device induces a magnetic field in the wire rope or cable and senses any deviation in the magnetic field indicating an anomaly in the wire rope or cable.
2. Description of the Prior Art
Polish Patent No. 45,862 discloses an induction sensor of a measuring head for the inspection of cables. The induction sensor has a two-part frame with cutouts of different diameter in which are located two bifilar coils connected in series and arranged concentrically with respect to the axis of the sensor and separately in the upper and lower parts of the frame.
Polish Patent No. 122,500 discloses two devices for the inspection and quality control of steel cables. According to each device a cable is magnetized by a magnetic field set up by a circuit which includes permanent magnets, the steel cable and pole pieces which are attached to the permanent magnets and include sliding guides which contact the steel cable.
The devices disclosed in Polish Patent No. 122,500 have several serious drawbacks. First, the inclusion of the pole pieces and sliding guides, some of which are necessarily made of ferrous material, makes the devices quite large and quite heavy. In addition, due to the large size of these devices, they require that the cable undergoing testing be contacted by the sliding guides which are subject to failure due to frictional erosion after a certain period of use.